Modified Surgical Stent in Management of Odontogenic Cyst in Mixed Dentition: A Report of Two Cases

The treatment choice in the management of odontogenic cysts in the mixed dentition period depends upon the size, location of the cyst, the bone integrity of the cystic wall, and its proximity to vital structures. Enucleation is indicated with smaller cysts, achieved by careful removal of a complete cyst without rupturing the cystic lining. Marsupializationand decompression are the treatments of choice for larger cysts as it can help to preserve the tooth bud of the successor tooth and reduce morbidity. Marsupialization is achieved by opening and deroofing the cyst, and making the cystic lining continuous with the oral cavity or surrounding structures by suturing the edges of the incised mucosa to the cystic wall. This helps in maintaining the patency of the cystic lesion. In the decompression, a cylindrical device (drain) is placed in the lesion, which maintains communication between oral cavity to cystic lesion. This decreases the intracystic pressure and results in bone formation. We present two cases of odontogenic cyst in children, where we used a modified decompression technique. We developed a modified surgical stent with the use of a Hawley’s appliance, which led to cystic decompression, and eventual eruption of the successor tooth. Notably, this modified technique also reduced both patient discomfort and the number of clinical visits, making it an effective treatment option. The unique design of the appliance also acted as a space maintainer for the eruption of successor tooth, which is very critical in mixed dentition for future prevention of space loss and eventual malocclusion. The advantage of our design was its easy removal and insertion with minimal discomfort.


Introduction
Enucleation, marsupialization, and decompression are the treatments of choice for the management of odontogenic cysts. Enucleation consists of the careful removal of a complete cyst without rupturing the cystic lining, particularly indicated with smaller cysts. With larger cysts, however, enucleation can lead to mandible fracture, devitalisation of the adjacent teeth, and amputation of the successor tooth buds suggesting marsupialization and decompression are the more viable options [1].
Marsupialization is achieved by opening and deroofing the cyst, and making the cystic lining continuous with the oral cavity or surrounding structures by suturing the edges of the incised mucosa to the cystic wall. This helps in maintaining the patency of the cystic lesion.
Sometimes, medicated gauze is inserted into the cystic lesion to prevent its spontaneous closure [2][3]. In the decompression technique, a drain is placed in the lesion, which maintains communication between oral cavity to cystic lesion. This decreases the intracystic pressure and results in bone formation [4].
The purpose of this article is to report two cases of odontogenic cyst in the mixed dentition period, treated with a modified decompression technique (Figure 1a (Figure 3b). Based on the clinical, radiographic, and histological findings the lesion was diagnosed as dentigerous cyst. Consequently, modified surgical stent was considered after discussion with parents.
The decision of utilizing modified surgical stent was based on positive outcome of case study 1 as well as parental reluctance for regular visits to hospital. As described in case study 1, Hawley's appliance was constructed from an alginate impression of the upper arch.
A nasotracheal tube (size-3) was passed through the

Discussion
The treatment choice in the management of odontogenic cysts in the mixed dentition period depends upon the size and location of the cyst, the bone integrity of the cystic wall and its proximity to vital structures. Masuda et al. [6] reported that in young children, enucleation should be avoided if the cyst is in close proximity to the developing tooth germ and other anatomical structures.
Instead, marsupialization is recommended [6]. Many surgeons recommend enucleation following marsupialization in order to remove the pathological cystic lining and prevent the recurrence of the cyst [2,4]. However, extensive research has shown that marsupialization/ decompression alone is a sufficient method of treatment of large jaw cysts, especially in young children, because it facilitates good bone regeneration and normal eruption of permanent tooth [2,4,[6][7][8][9][10][11][12]. In marsupialization technique, a part of the cystic lining is removed to create a surgical window to expose the cystic lesion to the oral cavity. This is followed by suturing the exposed cystic boundaries to the adjacent mucosa, whereas in the decompression technique, a drain is placed in the lesion, which maintains communication between oral cavity to cystic lesion. This decreases the intracystic pressure and results in bone formation. The main difference between these two techniques is the use of any device or drain instead of suturing of cystic lining to adjacent mucosa to prevent the closure of the mucosa. In both the techniques, a decrease of the intraluminal pressure/volume helps in resolving the cystic lesion [4].
In our cases, there was a close proximity of the tooth bud to cystic lining. Enucleation would have damaged the underlying tooth bud. Hence, we preferred to undertake decompression. The surgical procedure in our patients included the extraction of the involved deciduous tooth, the collection of incised pathological tissue for microscopic examination, and the establishment of an access point through the extracted socket into the body of cystic lesion. In both described cases, good bone healing with a normal eruption of the displaced permanent tooth was subsequently observed. The main purpose behind marsupialization /decompression is to make an opening or create an adequate window on the outer wall of cyst through which the cystic content is evacuated. This leads to the gradual ossification and size reduction of the cyst to an extent that the cystic lining becomes continuous with the oral epithelium [3,7]. This suggests that decompression within a bony cyst may dramatically promote the active growth potential of bone and the eruption of the tooth germ in the mixed dentition period. Various authors have reported successful results with different decompression technique. Oliveros-Lopez et al. [11] in their study effectively utilized decompression tube passing through surgically induced bony window over cystic wall. CarvanoandLuna [12] in their case series used a transalveolar silicone drain for decompression of dentigerous cyst in mixed dentition period. Nawaz et al. [13] reported the use of simple multipurpose acrylic splint in rehabilitation of radicular cyst in mixed dentition. Ziccardi et al. [14] in their case report used a simple fenestration technique for management of large dentigerous cyst.
However, the main drawback of decompression in children is patient compliance as it involves frequent clinical visits and prolonged treatment till the eruption of successor. Principally, the patency of the cystic lumen is maintained either by tightly packing sterilized gauze or by means of silicon drain or decompression tube, which requires frequent dressing changes and cystic cavity irrigation by clinician [3,[11][12]. During a dressing change, a patient may experience extensive pain and fresh bleeding. Although our children reported moderate pain during change of gauge, it was sufficient enough to make them highly uncooperative in subsequent appointments. Our patient's parents also showed reluctance for frequent visits. To overcome these shortcomings, we utilized a Hawley's appliance to provide a stable template for the nasotracheal tube and to maintain continuous drainage from the cystic lesion into the oral cavity. The unique design of the appliance not only decompressed the cyst but also maintained the space for the eruption of successor tooth. The advantage of our design was its easy removal and insertion with minimal discomfort. Patients showed remarkable acceptance once they understood the path of insertion and removal of the appliance. They were able to maintain good oral and appliance hygiene. During food consumption, an acrylic stopper was inserted into to the oral end of the tube. This prevented the food, getting lodged into the tube. Our appliance reduced the number of visits and improved compliance and cooperation of our patients.
Moreover, the easy fabrication of the appliance makes modified surgical stent in marsupialization an effective option. Both the patients gave a satisfactory feedback on the acceptability of the appliance in their feedback forms post treatment.
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conclusion
Modified surgical stent is an effective and conservative approach of marsupialisation for large odontogenic cysts in mixed dentition. This appliance reduces the frequent clinical visits, maintains space for permanent dentition in children.